/**
 * @param {number[][]} lines
 * @param {number} start
 * @param {number} end
 * @return {number[]}
 */
 var metroRouteDesignI = function(lines, start, end) {
  const map = new Map()
  for(let i = 0; i<lines.length; i++){
    for(let s of lines[i]){
      if(!map.has(s)) map.set(s, [])
      map.get(s).push(i)
    }
  }
  // 找到中转的站点   连接两天线路的站点
  const cross = new Map()
  const arr = [...map.keys()].filter(v => map.get(v).length > 1)
  for(let x of )
  // 起始线路  终点线路
  let ss = map.get(start), es = map.get(end)
  
  return []
};


class TreeNode{
  constructor(val){
    this.val = val
    this.children = []
    this.station = []
  }
}